In the multivariate analysis with adjustment for all parameters found to be associated with moderate-severe anaemia, IgM positivity and not PCR positivity remained associated with moderate-severe anaemia (IgM: OR: 2.6, 95%-CI: 1.3–5.3; P < 0.01; PCR: OR: 0.9; 95%-CI: 0.4–1.8; P = 0.70), Similarly, the median Hb-level was lower (9.0 g/dl vs. 10.1 g/dl; P = 0.08). The gene discussed is GSTM1; the disease is anemia (phenotype).